Abstract: A plant monitoring device (20) is provided with: a detection value acquisition unit (211) that acquires a bundle of detection values; a first Mahalanobis distance calculation unit (212) that calculates a first Mahalanobis distance by using as a reference a unit space generated on the basis of a bundle of past detection values; a first SN ratio calculation unit (214) that calculates a first SN ratio for each of a plurality of evaluation items; a second Mahalanobis distance calculation unit (215) that calculates a second Mahalanobis distance by increasing or decreasing each of the detection values; a second SN ratio acquisition unit (216) that converts the first SN ratio for each of the evaluation items and acquires a second SN ratio on the basis of the first and second Mahalanobis distances; and an addition unit (217) that calculates an added value of a plurality of the second SN ratios acquired within a prescribed period for each of the evaluation items.

Abstract: A plant monitoring method using a Mahalanobis distance calculated from data of a plurality of variables indicating the state of the plant. The plant monitoring method includes: acquiring data in a first period in the past up to the current point of time as first data; predicting data in a second period from the current point of time as second data; and creating, on the basis of the first data and the second data, a unit space that serves as a base for calculating the Mahalanobis distance. In the prediction step, the second data is predicted on the basis of: data in a third period obtained, as third data, by shifting the first period to the past by a prescribed period; data in a fourth period obtained, as fourth data, by shifting the second period to the past by the prescribed period, and the first data.

Abstract: Provided are a diagnosing device, a diagnosing method, and a program with which it is possible to detect abnormalities accurately even if there is a small amount of data or the number of data points varies. This diagnosing device is provided with a Mahalanobis distance calculating unit which calculates the Mahalanobis distance (referred to as ‘MD value’ hereinbelow) of a detected value, and an abnormality determining unit which determines the presence or absence of an abnormality on the basis of the MD value, wherein the abnormality determining unit determines the presence or absence of an abnormality by arranging that a determination that there is no abnormality is more likely to occur if the number of samples per unit space is small than if the number of samples per unit space is large.

Abstract: A unit space update device, which generates a unit space, includes: a detection value acquisition unit which acquires a bundle of detection values detected at a constant cycle; and a deletion processing unit which deletes one bundle from the bundles of the detection values constituting the unit space, when adding the bundle of the detection values to the unit space. The deletion processing unit includes at least one among: a first processing unit which randomly deletes one bundle from the bundles of the detection values forming the unit space; and a second processing unit which, with respect to the detection value of the predetermined evaluation item among the plurality of evaluation items, deletes any one bundle of the bundles including the detection value with the highest appearance frequency in the unit space, or one of two bundles having the smallest difference between the detected values in the unit space.

Abstract: An acquisition unit acquires a bundle of detection values for each of a plurality of sensor values pertaining to a plant. A distance calculation unit obtains the Mahalanobis distance of the bundle of detection values acquired by the acquisition unit using, as reference, a unit space constituted by a collection of bundles of detection values for each of the plurality of sensor values. A determining unit determines, based on whether the Mahalanobis distance is at or within a prescribed threshold, whether the operation state of the plant is normal or abnormal. A trend specification unit specifies a trend with regards to at least one sensor value. An abnormality cause estimation unit estimates an abnormality cause based on the trend for the sensor value(s), and a fault site estimation database for holding the relationship between abnormality causes that may occur in the plant and sensor values for each of the trends.

Abstract: An acquisition unit is configured to acquire measurement values of a target device. The measurement values that are acquired include at least a temperature and a flow rate of an input fluid to be input to the target device, and a temperature and a flow rate of an output fluid to be output from the target device. A correction unit is configured to obtain a correction measurement value by which the measurement values are corrected through thermal equilibrium calculations based on the measurement values. A distance calculation unit is configured to calculate a Mahalanobis distance with a factor of the correction measurement value.

Abstract: A plant monitoring device (20) is provided with: a detection value acquisition unit (211) that acquires a bundle of detection values; a first Mahalanobis distance calculation unit (212) that calculates a first Mahalanobis distance; a plant state determination unit (213) that determines whether the operation state of a plant is normal or abnormal; a cause detection value estimation unit (214) that estimates a cause detection value which represents a cause of the abnormality of the plant; a second Mahalanobis distance calculation unit (215) that calculates a second Mahalanobis distance by increasing or decreasing the detection value estimated as the cause detection value; and an identification unit (216) that identifies whether the abnormality can be relieved by increasing or decreasing the detection value estimated as the cause detection value.

Abstract: Provided are a diagnosing device, a diagnosing method, and a program with which it is possible to detect abnormalities accurately even if there is a small amount of data or the number of data points varies. This diagnosing device is provided with a Mahalanobis distance calculating unit which calculates the Mahalanobis distance (referred to as ‘MD value’ hereinbelow) of a detected value, and an abnormality determining unit which determines the presence or absence of an abnormality on the basis of the MD value, wherein the abnormality determining unit determines the presence or absence of an abnormality by arranging that a determination that there is no abnormality is more likely to occur if the number of samples per unit space is small than if the number of samples per unit space is large.

Abstract: A plant monitoring device (20) is provided with: a state quantity acquiring unit (211) which acquires state quantities for each of a plurality of characteristic items relating to a plant; an abnormality degree calculating unit (212) which calculates a degree of abnormality representing a degree of approach toward an abnormal side relative to a limit value that is predetermined for each characteristic item, for the state quantities acquired at a plant monitoring timing; a distance calculating unit (213) which uses a statistical technique to calculate distances representing the degrees of separation, from the normal operating state of the plant, of the state quantity and the degree of abnormality acquired at the monitoring timing; and a determining unit (214) which determines the operating state of the plant on the basis of the calculated distances.

Abstract: An acquisition unit is configured to acquire measurement values of a target device. A likelihood calculation unit is configured to calculate an occurrence likelihood for each of a plurality of phenomena that are liable to occur to the target device based on the measurement values acquired by the acquisition unit. A table storage unit is configured to store a table in which the plurality of phenomena and occurrence causes of abnormalities of the target device are associated to each other. As estimation unit is configured to estimate the occurrence causes based on the occurrence likelihood and the table.

Abstract: A unit space generating device (141) which generates a unit space for use when diagnosing an operating state of a plant on the basis of a Mahalanobis distance is provided with: a sampling data acquiring unit (141A) which acquires a sampling data group comprising a plurality of state quantities of the plant, measured with a fixed period; an adoption determining unit (141C) which, on the basis of an adoption probability calculated each time the sampling data group is acquired, determines whether the sampling data group is to be adopted as a unit space generation data group serving as the basis for a unit space; a unit space generating unit (141D) which generates unit spaces on the basis of a plurality of the adopted unit space generation data groups; and an output value acquiring unit (141B) which acquires an output value of the plant corresponding to the sampling data group.

Abstract: A plant monitoring device (20) is provided with: a detection value acquisition unit (211) that acquires a bundle of detection values; a first Mahalanobis distance calculation unit (212) that calculates a first Mahalanobis distance; a plant state determination unit (213) that determines whether the operation state of a plant is normal or abnormal; a cause detection value estimation unit (214) that estimates a cause detection value which represents a cause of the abnormality of the plant; a second Mahalanobis distance calculation unit (215) that calculates a second Mahalanobis distance by increasing or decreasing the detection value estimated as the cause detection value; and an identification unit (216) that identifies whether the abnormality can be relieved by increasing or decreasing the detection value estimated as the cause detection value.

Abstract: A unit space update device, which generates a unit space, includes: a detection value acquisition unit which acquires a bundle of detection values detected at a constant cycle; and a deletion processing unit which deletes one bundle from the bundles of the detection values constituting the unit space, when adding the bundle of the detection values to the unit space. The deletion processing unit includes at least one among: a first processing unit which randomly deletes one bundle from the bundles of the detection values forming the unit space; and a second processing unit which, with respect to the detection value of the predetermined evaluation item among the plurality of evaluation items, deletes any one bundle of the bundles including the detection value with the highest appearance frequency in the unit space, or one of two bundles having the smallest difference between the detected values in the unit space.

Abstract: A diagnostic device includes a storage unit that stores first information including a first abnormal event which occurred in the past in a plant, a first attribution event that is a cause of the first abnormal event, and a first occurrence probability of the first attribution event, in which a causal relationship between the first abnormal and attribution events is indicated by a tree structure, and second information including a second abnormal event which is supposed to occur in the plant but has not yet occurred, a second attribution event that is a cause of the second abnormal event, and a second occurrence probability of the second attribution event, in which a causal relationship between the second abnormal and attribution events is indicated by a tree structure; and an estimation unit that estimates the cause of the sign of the abnormality, based on the first and second information.

Abstract: A unit space generating device (141) which generates a unit space for use when diagnosing an operating state of a plant on the basis of a Mahalanobis distance is provided with: a sampling data acquiring unit (141A) which acquires a sampling data group comprising a plurality of state quantities of the plant, measured with a fixed period; an adoption determining unit (141C) which, on the basis of an adoption probability calculated each time the sampling data group is acquired, determines whether the sampling data group is to be adopted as a unit space generation data group serving as the basis for a unit space; a unit space generating unit (141D) which generates unit spaces on the basis of a plurality of the adopted unit space generation data groups; and an output value acquiring unit (141B) which acquires an output value of the plant corresponding to the sampling data group.

Abstract: A collection device includes a reception unit, a first inspection unit, and a first transmission request unit. The reception unit receives a data unit including operation data indicating an operation state of a plant and a guarantee value for guaranteeing authenticity of the operation data. The first inspection unit inspects the authenticity of the data unit by inspecting a quality of the data unit on the basis of the guarantee value and by inspecting the presence or absence of a loss of the data on the basis of a reception interval of the data unit. The first transmission request unit requests a transmission side of the data unit to retransmit the data unit when inspection results of the first inspection unit indicate no authenticity.

Abstract: A diagnostic device includes a storage unit that stores first information including a first abnormal event which occurred in the past in a plant, a first attribution event that is a cause of the first abnormal event, and a first occurrence probability of the first attribution event, in which a causal relationship between the first abnormal and attribution events is indicated by a tree structure, and second information including a second abnormal event which is supposed to occur in the plant but does not occur yet, a second attribution event that is a cause of the second abnormal event, and a second occurrence probability of the second attribution event, in which a causal relationship between the second abnormal and attribution events is indicated by a tree structure; and an estimation unit that estimates the cause of the sign of the abnormality, based on the first and second information.

Abstract: An acquisition unit is configured to acquire measurement values of a target device. The measurement values that are acquired include at least a temperature and a flow rate of an input fluid to be input to the target device, and a temperature and a flow rate of an output fluid to be output from the target device. A correction unit is configured to obtain a correction measurement value by which the measurement values are corrected through thermal equilibrium calculations based on the measurement values. A distance calculation unit is configured to calculate a Mahalanobis distance with a factor of the correction measurement value.

Abstract: An acquisition unit is configured to acquire measurement values of a target device. A likelihood calculation unit is configured to calculate an occurrence likelihood for each of a plurality of phenomena that are liable to occur to the target device based on the measurement values acquired by the acquisition unit. A table storage unit is configured to store a table in which the plurality of phenomena and occurrence causes of abnormalities of the target device are associated to each other. As estimation unit is configured to estimate the occurrence causes based on the occurrence likelihood and the table.

Abstract: A method for producing a turbine blade includes performing brazing treatment, performing annealing, and subjecting a base material to solutionizing treatment. In the brazing treatment, a brazing material is welded to be joined to the base material of a turbine blade by operating a heater to perform heating at a first temperature under a state in which the base material having the brazing material arranged thereon is placed in a predetermined heating furnace including the heater. In annealing, the base material is cooled by stopping the heater and lowering a furnace internal temperature after the brazing treatment. In the solutionizing treatment, ductility of the base material is improved through heating at a second temperature lower than the first temperature after the annealing.